The present invention relates to a medium recording and reproducing apparatus and a medium recording and reproducing method, and more particularly to the handling of defect lists (DFL) in an apparatus that records and reproduces data using a data recording area reserved for spare area recording on a medium.
Today, recording and reproducing apparatuses are available that use a semiconductor laser to focus a laser beam onto an optical disc-like recording medium for recording. Those apparatuses include a CD-R/RW (CD Recordable/Rewritable), DVD±R/RW (DVD±Recordable/Recordable Disc), DVD-RAM (DVD-Rewritable), and Blu-ray Disc (hereinafter called a BD). A defective part (defect) is sometimes generated on a rewritable or recordable optical disc medium, for example, by a scratch caused in a part of the medium, fingerprints, contamination, or recording film degradation. If data is recorded in such a defective part, there is a high possibility that data cannot be read.
As one of the methods for avoiding recording in a defect on the disc surface and prolonging the disc life, the defect management method, called Linear Replacement, is provided for recording data, not in the defective part, but in an spare area (alternative recording area) reserved on the same optical disc. This method, which is applied to a DVD-RAM, is described in pages 29-31 in “DVD-RAM Technology” by TRICEPS Planning Department, TRICEPS Co., 2000. This technology is applied also to a BD and if, while data is recorded in the user data area on a cluster basis, data cannot be recorded in a cluster or data is successfully recorded in a cluster but cannot be successfully verified, the cluster is recorded in an spare area provided on the disc. A cluster is the minimum recording block unit in which data is recorded in the present invention. And, the address information on a detected defective cluster and the address information on a cluster in the spare area in which data is recorded are registered as the defect lists (DFL) in the management area provided on the disc. Several types of DFL are defined. For example, a DFL is registered as a reallocated defect entry (RAD: Re-allocated Defect) when the defective area is composed of one cluster only, and as a contiguous reallocated defect entry (CRD: Contiguous Re-allocated Defect) when the defect area is composed of contiguous two or more clusters. For example, when a defect is found in ten contiguous clusters, ten DFLs are required for RAD entry registration while only two DFLs are required for CRD entry registration and, as a result, the number of DFLs registered in the management area is reduced. This is described in JP-A-2008-510263. At reproduction time, the DFLs are read to read data, not from the cluster position specified by the recording instruction from a higher level device, but from the cluster in which data has been written alternatively.